Alzheimer's disease (AD) is an insidious affliction which cripples the cognitive capabilities of its victims. While memory complaints are the hallmark of the illness, perceptual disorders also are prevalent. Recent psychophysical research has demonstrated that there is a significant disturbance in the spatial contrast sensitivity of Alzheimer patients. The evidence suggests that the visual experience of the Alzheimer patient is very different from that of healthy, elderly adults. The major objective of the research project is to examine the hypothesis that a portion of the AD patient's deficit in reading speed and comprehension may be due to their poor contrast sensitivity. It is suggested that the contrast sensitivity deficit creates a data limitation which hinders the higher order processing of visual stimuli. It is hypothesized that the data limitation may be reduced by contrast enhancement of text material. If contrast enhancement is effective in modifying the reading speed and immediate comprehension for text, then the role of the contrast deficit in these processing areas will have been demonstrated. Furthermore, an effective intervention tool for improving the reading performance of Alzheimer disease patients will have been illustrated. The objective will be explored through three specific aims using the tools of visual psychophysics and image engineering technology. The first aim is to improve oral reading speed through contrast enhancement of reading material. A standardized video-based reading test, the Minnesota Low- Vision Reading Test, will be used to determine the optimum character size, contrast, and spatial frequency composition of textual material. The second aim is to demonstrate the efficacy of contrast enhancement for improving the immediate retention of visually presented material. It is hypothesized that by easing the data-limitation processing burden, the AD patient will be able to devote more cognitive resources to higher order processes, such as memory. The third aim is to demonstrate that both immediate and longer term gains in comprehension may be associated with the use of text material which has been constructed to be visually optimal for the AD patient. The major outcomes of the project will be (1) the determination of optimum stimulus characteristics for effective oral reading by AD patients, (2) the demonstration of the effectiveness of stimulus enhancement for producing immediate memory improvement, and (3) the demonstration of comprehension gains associated with the use of visually fair text material.